Henderson had been jailed since 1982. She was sentenced to life in prison with no chance of parole for a robbery that left Springfield jeweler Harry Klein dead. Investigators have said Henderson persuaded Klein to drive out of town with her but he was shot to death by Henderson's boyfriend.

Greitens noted Wednesday that the judge at Henderson's trial said she played a "relatively minor" role in the crime. Supporters also said she received inadequate representation from her attorney.